The present invention relates to a panel with a frame (which will be hereinafter referred to as a panel unit), and also relates to a method for manufacturing such a panel unit.
It is known that a frame to be mounted on a peripheral edge of a panel such as a window glass for a vehicle is linearly molded by extruding synthetic resin, rubber or the like. The linear molding for the frame is then mounted on the peripheral edge of the panel and bonded thereto with a portion of the frame bent at each corner portion of the panel.
In such a conventional panel unit to be manufactured by employing a linear molding, much time and labor are required in mounting the frame on the peripheral edge of the panel and bonding the frame thereto. Furthermore, there is a possibility of wrinkling and floating of the frame at each corner portion of the panel or in the vicinity thereof. This tends to impair appearance of the panel.
A technique of eliminating the awkward operation in mounting the frame on the peripheral edge of the panel is disclosed in Japanese Laid-open Patent Publication No. 63-15716, for example.
According to this prior art technique, a panel is set within a pair of injection molding dies, and the dies are closed. Then, molding material such as resin and rubber is injected into a cavity defined around the peripheral edge of the panel, thereby forming a frame on the peripheral edge of the panel.
However, in the case that the panel is large in size, the cost of manufacturing the injection molding dies becomes high. This will increase the cost of manufacturing the panel unit.
Furthermore, in closing the injection molding dies, a closing pressure is applied to the panel which tends to damage the panel. Additionally, the molding surface of the dies is marred by the damaged panel, resulting in surface defects of the frame.
A technique for forming the frame on the peripheral edge of the panel is disclosed in the U.S. Pat. No. 5,057,265 by Kunert et al.
In this prior art technique, a frame is formed along the peripheral edge of a panel. However, such a technique does not permit formation of a frame which covers a part of the upper and lower surfaces and the end surface of the panel. Also, such a technique, if there is a variation in the external dimension of the panel, does not provide a panel unit having a predetermined external dimension.
It is, accordingly, an object of the present invention to provide a panel unit which can eliminate the awkward operation in mounting a frame on the peripheral edge of a panel and prevent wrinkling and floating of the frame at each corner portion of the panel or in the vicinity thereof.
It is another object of the present invention to provide a panel unit having a frame which is formed on the peripheral edge of a panel so as to cover a part of the upper and lower surfaces and the end surface of the panel, and having a predetermined external dimension.
It is a further object of the present invention to provide a method for manufacturing such a panel unit easily at low costs.
According to a first aspect of the present invention, there is provided a panel unit comprising a window glass panel, and a frame continuously formed on a peripheral edge of the window glass by extrusion molding and simultaneously bonded to the peripheral edge of the window glass panel, the frame being formed on the peripheral edge of the window glass panel so as to cover a part of the upper and lower surfaces and the end surface of the window glass panel.
The frame is continuously formed on the peripheral edge of the window glass panel by extrusion molding and is simultaneously bonded thereto. Accordingly, the awkward operation in mounting the frame along the peripheral edge of the window glass panel is eliminated. Further, wrinkling and floating of the frame at each corner portion of the panel or in the vicinity thereof is prevented.
The frame is formed on the peripheral edge of a panel so as to cover a part of the upper and lower surfaces and the end surface of the panel. Accordingly, the frame may effectively protect the peripheral edge of the panel. The frame may also cover an adhesive which is used to bond the frame to the panel, thereby to prevent the adhesive from deterioration by ultraviolet light.
According to a second aspect of the present invention, there is provided a method of manufacturing a panel unit including a window glass panel, and a frame mounted on a peripheral edge of the window glass panel. The method comprises the steps of providing a window glass panel, preparing molding die means having an extrusion port for extruding a molding material, the extrusion port having an inner circumferential surface configured to a cross section of a frame to be mounted on the peripheral edge of the window glass panel, and an open side surface shaped to externally receive the peripheral edge of the window glass panel, inserting a part of the peripheral edge of the window glass panel into the open side surface of the extrusion port to form a molding space defined by the peripheral edge of the window glass panel and the inner circumferential surface of the extrusion port, the molding space corresponding to the cross section of the frame and having an opening, extruding the molding material from the extrusion port of the molding die means into the molding space, and providing continuous movement of the window glass panel relative to the molding die means so that the extrusion port of the molding die means is virtually moved around the peripheral edge of the window glass panel, thereby forming the frame covering end surface and a part of the upper and lower surfaces of the window glass and extending along the peripheral edge of the window glass.
The method may permit manufacturing such a panel unit having a frame which covers a part of the upper and lower surfaces and the end surface of a panel at low costs.
Other objects and features of the invention will be more fully understood from the following detailed description and appended claims when taken with the accompanying drawings.